Very Low Audio in DVD Studio

Question

Very Low Audio in DVD Studio

FCP project with 20 short timelines -- all single video tracks, stereo audio tracks, two filters: EQ (to pump highs and lows), Compression (to make it pop just below zero DB), and sometimes a little gain.
All rendered, of course. The 20 timelines go two directions in Compressor: to H.264 via a Matrox Mini, and to the standard Best DVD compressor which makes the M2V video and the AC3 audio files. The H.264 file is the same audio level as the FCP timelines -- pretty hot at just below zero DB. BUT, the DVD audio files are way low -- maybe a third of the original audio. Why? Is Compressor or DVD Studio Pro "interpreting" the audio somehow? Almost feels its adding a limiter to the AC3 file.

MacPro Octo, MatroxOX2 MAX, MacBook Pro C2D 2G, iMac, iPad, iPhone 4 & 3GS, Mac OS X (10.6.6), Final Cut Pro Studio 7.0.2, AG-HVX200

Posted on Jan 20, 2011 4:19 PM

Reply

Answer 1

Jan 20, 2011 6:33 PM in response to David Ahrendts

In Compressor, duplicate the AC3 (Dolby Digital) preset, then change the Dialog Normalization to -31bdfs and the Compression to NONE. The resulting audio should be as it was in FCP after using the modified preset.

-DH

Reply

Answer 2

Jan 20, 2011 7:14 PM in response to David Harbsmeier

David, thank you x100! That indeed solved the audio discrepancy. I'm curious about the intent and design of this well-used pre-set in Compressor. Was the intent to make more dynamic audio range? So if an audio track came in at 0db, it gets knocked down to much less? And, what is Dialog Normalization?
Again, many thanks. You saved my small project. Several of them actually.

Reply

Answer 3

Jan 26, 2011 11:44 AM in response to David Harbsmeier

What is DIALOG NORMALIZATION in this audio setting. What is BDFS?

Reply

Answer 4

Jan 26, 2011 3:33 PM in response to David Ahrendts

Sorry ... I made a typo in my first reply. Instead of -31bdfs it should have read "-31dbfs"

dbfs stands for 'Decibels relative to Full Scale': http://en.wikipedia.org/wiki/DBFS

And here's a really old article on creating AC3 files with A.Pack, which was what we all used with older versions of DVD Studio Pro before Compressor had the ability to encode AC3. While it's pretty old, the information about the settings is still valid: http://www.kenstone.net/fcphomepage/a_packwarmouth.html

-DH

Reply

Answer 5

Jan 26, 2011 7:18 PM in response to David Harbsmeier

Ah, A.Pack. It's fun to see that article. Raise your hand if you used M.Pack.

Reply

Answer 6

Jan 27, 2011 9:14 AM in response to Jeremy Hansen

When we were lucky enough to have a tour round the BBCs 5.1 sound facility (and also their restoration facility) the guy running the department asked what we used for Dialog Norm and we said -31... which is what he would use... so good enough for the BBC 🙂

Reply

Answer 7

Hal MacLean

Level 6

14,833 points

Jan 31, 2011 2:47 PM in response to Steve Kirkham

Totally agree Steve - the BBC have said the same to me in the past 🙂

Dialogue Normalization is a funny old setting - it actually refers to the amount of attenuation applied to the audio source with -31db meaning no attenuation, which should mean that the volume of the audio is preserved throughout the compression process.

There's a lot more to this, of course, have a look here for some plain explanations:

http://www.hometheaterhifi.com/volume72/feature-article-dialog-normalization-6-2000.html

Reply

Answer 8

FLAV1975

Level 1

0 points

Mar 13, 2011 10:39 PM in response to David Harbsmeier

Hello I saw your answer to "Very Low Audio in DVD Studio Pro" I made a simple DVD using Best dvd 90 mins in compressor. I has previously mixed the the timeline sequence in FCP and was satisfied with the mix. When I made the DVD, the sound seemed low and even when I tried to raise the volume on the TV it was still a little low.

How do you find a dialnorm option on compressor? I am using compressor 3.5

Reply

Answer 9

Mar 13, 2011 10:50 PM in response to FLAV1975

How do you find a dialnorm option on compressor? I am using compressor 3.5

My reply to the OP above applies to your question as well. I'll paste it here for you to review:

In Compressor, duplicate the AC3 (Dolby Digital) preset, then change the Dialog Normalization to -31bdfs and the Compression to NONE. The resulting audio should be as it was in FCP after using the modified preset.

-DH

Reply

Answer 10

Mar 18, 2011 7:58 AM in response to David Harbsmeier

Hey
I you have to check the levels in FCP if its ok then you have to go to the next step in compressor.
Making DVD file i.e M2V and AC3 you have to check the setting of Audio file.
Compressor>> AC3 settings in inspector>>Encoder>>Preprocessing>>compression preset>>None.
Thats it your problems is solved.
But do remember if your original volume is low then you have to increase it the apply these settings.

-Abhishek Masih

Reply

Answer 11

Jun 13, 2015 5:44 AM in response to David Harbsmeier

Nice ! Thanks a lot ! 🙂

Sounds good, my mix level is now as expected ✅

Just for information, the screenshots in Compressor 4.2:

Original AC3 settings:

Modified settings:

Reply

Answer 12

nick1981

Level 1

1 points

Dec 9, 2015 8:56 AM in response to David Harbsmeier

I know this was posted awhile ago, but I'm having the same issue. I have one question. I've just duplicated the AC3 (Dolby Digital) preset. Now, do I modify both the duplicate and the original AC3 preset, or should I modify only the duplicate I just added?

thanks

Reply

Answer 13

nick1981

Level 1

1 points

Dec 9, 2015 9:59 AM in response to nick1981

Actually what do you mean when you say "duplicate" the audio? I dragged/added a second AC3 file in compressor, which compressor successfully encoded. But then, DVD Studio Pro does not allow me to add two AC3 files for one video file. What should I do?

Reply

Answer 14

Dec 11, 2015 8:24 PM in response to nick1981

>>do I modify both the duplicate and the original AC3 preset, or should I modify only the duplicate I just added?<<

You only need to modify the duplicate preset - I'm not sure you even can modify the original.

>>Actually what do you mean when you say "duplicate" the audio? I dragged/added a second AC3 file in compressor<<

No need to duplicate the audio file itself - just the audio preset in Compressor so you can modify the settings.

-DH

Reply